Refining Operative Strategies for Optic Nerve Decompression: A Morphometric Analysis of Transcranial and Endoscopic Endonasal Techniques Using Clinical Parameters

2017 ◽  
Vol 14 (3) ◽  
pp. 295-302 ◽  
Author(s):  
Steven L Gogela ◽  
Lee A Zimmer ◽  
Jeffrey T Keller ◽  
Norberto Andaluz

Abstract BACKGROUND Various approaches can be considered for decompression of the intracanalicular optic nerve. Although clinical experience has been reported, no quantitative study has yet compared the extent of decompression achieved by an endoscopic endonasal versus transcranial approach. OBJECTIVE Toward this aim, our morphometric analysis compared both approaches by quantifying the circumferential degree of optic canal decompression that is possible before any meningeal violation, which would result in cerebrospinal fluid (CSF) leak. METHODS From 10 cadaver heads, 20 optic canals were sequentially decompressed using an endoscopic endonasal approach and pterional craniotomy with extradural clinoidectomy. Dissections ended before violation of the sphenoid sinus during the transcranial approach, and before intracranial transgression from the endonasal corridor. Based on our study criteria, decompressions were not maximal for either approach, but were maximal before violating the other compartment. Decompression achieved from each approach was quantified using CT scans for each stage. RESULTS Greater circumferential bony optic canal decompression was obtained from transcranial (245.2°) than endonasal (114.8°) routes (P < .001). By endonasal perspective, the anatomical point where the optic nerve traverses intracranially was approximated by the medial border of the anterior ascending cavernous internal carotid artery. CONCLUSION Our morphometric analysis comparing optic canal decompression for endonasal and transcranial corridors provides important guidance for this location. Ample visualization and wide exposure can be achieved via a transcranial approach with limited risk of CSF leak. A landmark, where the intracanalicular segment ends and optic nerve traverses intracranially, can mark the extent of decompression safely obtained before risking CSF leak.

2012 ◽  
Vol 32 (Suppl1) ◽  
pp. E8 ◽  
Author(s):  
Juan C. Fernandez-Miranda ◽  
Carlos D. Pinheiro-Neto ◽  
Paul A. Gardner ◽  
Carl H. Snyderman

The authors present the technical and anatomical nuances needed to perform an endoscopic endonasal removal of a tuberculum sellae meningioma. The patient is a 47-year-old female with headaches and an incidental finding of a small tuberculum sellae meningioma with no vascular encasement, no optic canal invasion, but mild inferior to superior compression of the cisternal segment of the left optic nerve. Neuroophthalmology assessment revealed no visual defects. Treatment options included clinical observation with imaging follow-up studies, radiosurgery, and resection. The patient elected to undergo surgical removal and an endonasal endoscopic approach was the preferred surgical option. Preoperative radiological studies showed the presence of an osseous ring between the left middle and anterior clinoids, the so-called carotico-clinoidal ring. The surgical implications of this finding and its management are illustrated. The surgical anatomy of the suprasellar region is reviewed, including concepts such as the chiasmatic sulcus and limbus sphenoidale, medial and lateral optico-carotid recesses, and the paraclinoidal and supraclinoidal segments of the internal carotid artery. Emphasis is made in the importance of exposing the distal dural ring of the internal carotid artery and the precanalicular segment of the optic nerve for adequate intradural dissection. The endonasal route allows for early coagulation of the tumor meningeal supply and extensive resection of dural attachments, and importantly, provides an inferior to superior access to the infrachiasmatic region that facilitates complete tumor removal without any manipulation of the optic nerve. The lateral limit of dural removal is formed by the distal dural ring, which is gently coagulated after the tumor is resected. A 45° scope is used to inspect for any residual tumor, in particular at the entrance of the optic nerve into the optic canal and at the most anterior margin of the exposure (limbus sphenoidale). The steps for reconstruction are detailed and include intradural placement of dural substitute and extradural placement of the nasoseptal flap. The nuances for proper harvesting, positioning, and reinforcement of the flap are described. No lumbar drain was used. The patient had an uneventful recovery with no CSF leak or any other complications. Imaging follow-up at 6 months showed complete removal of the tumor. The patient had no sinonasal or neurological symptoms, and olfaction was fully preserved. The video can be found here: http://youtu.be/kkuV-yyEHMg.


2017 ◽  
Vol 127 (1) ◽  
pp. 199-208 ◽  
Author(s):  
Alberto Di Somma ◽  
Luigi Maria Cavallo ◽  
Matteo de Notaris ◽  
Domenico Solari ◽  
Thomaz E. Topczewski ◽  
...  

OBJECTIVEDifferent surgical routes have been used over the years to achieve adequate decompression of the optic nerve in its canal including, more recently, endoscopic approaches performed either through the endonasal corridor or the transorbital one. The present study aimed to detail and quantify the amount of bone removal around the optic canal, achievable via medial-to-lateral endonasal and lateral-to-medial transorbital endoscopic trajectories.METHODSFive human cadaveric heads (10 sides) were dissected at the Laboratory of Surgical Neuroanatomy of the University of Barcelona (Spain). The laboratory rehearsals were run as follows: 1) preliminary preoperative CT scans of each specimen, 2) anatomical endoscopic endonasal and transorbital dissections and Dextroscope-based morphometric analysis, and 3) quantitative analysis of optic canal bone removal for both endonasal and transorbital endoscopic approaches.RESULTSThe endoscopic endonasal route permitted exposure and removal of the most inferomedial portion of the optic canal (an average of 168°), whereas the transorbital pathway allowed good control of its superolateral part (an average of 192°). Considering the total circumference of the optic canal (360°), the transorbital route enabled removal of a mean of 53.3% of bone, mainly the superolateral portion. The endonasal approach provided bone removal of a mean of 46.7% of the inferomedial aspect. This result was found to be statistically significant (p < 0.05). The morphometric analysis performed with the aid of the Dextroscope (a virtual reality environment) showed that the simulation of the transorbital trajectory may provide a shorter surgical corridor with a wider angle of approach (39.6 mm; 46.8°) compared with the simulation of the endonasal pathway (52.9 mm; 23.8°).CONCLUSIONSUsed together, these 2 endoscopic surgical paths (endonasal and transorbital) may allow a 360° decompression of the optic nerve. To the best of the authors' knowledge, this is the first anatomical study on transorbital optic nerve decompression to show its feasibility. Further studies and, eventually, surgical case series are mandatory to confirm the effectiveness of these approaches, thereby refining the proper indications for each of them.


2013 ◽  
Vol 4 (1) ◽  
pp. ar.2013.4.0047 ◽  
Author(s):  
Deepa V. Cherla ◽  
Senja Tomovic ◽  
James K. Liu ◽  
Jean Anderson Eloy

Preoperative recognition of the Onodi cell is necessary to avoid injury to closely associated structures, including the internal carotid artery and the optic nerve. This article describes the central Onodi cell, a variation in which a posterior ethmoid cell lies superior to the sphenoid sinus in a midline position with at least one optic canal bulge. To our knowledge, this anatomic variation has not been previously reported in the literature. Radiographic and endoscopic imaging of this unique variation is provided.


2021 ◽  
Author(s):  
Devi P Patra ◽  
Evelyn L Turcotte ◽  
Bernard R Bendok

Abstract The optic canal (OC) is a bony channel that transmits the optic nerve (ON) and ophthalmic artery (OphA) as they course through the lesser wing of the sphenoid bone to the orbital apex. The OC is involved in a variety of intracranial and extracranial pathologies,1 and opening of the canal may be necessary in order to achieve adequate exposure, better disease control, and vision preservation.2 Depending on the location of the pathology and its relationship with the optic nerve, the OC may be decompressed through an open transcranial approach or an endoscopic endonasal approach.1,3 OC drilling can be tailored based on the location of the pathology and its extension. Anterior clinoid process and optic strut drilling can be added based on these factors as well.4,5 In this video, we demonstrate the steps of OC drilling in both transcranial microscopic and endoscopic endonasal approaches through a combination of animated illustrations and operative videos. We present 4 cases, including 2 transcranial microscopic and 2 endoscopic endonasal approaches,6 demonstrating OC decompression and its technical nuances. Each case was selected to represent the range of pathologies relevant to OC drilling to allow for a complete understanding of the techniques and concepts required for optimal treatment. An informed written consent has been obtained from each of the patients in this publication. Video © Mayo Foundation for Medical Education and Research. All rights reserved. Copyright information: Bendok BR, Abi-Aad KR, Sattur MG, Welz ME, Hoxworth JM, Lal D. Endoscopic resection of a paraclinoid meningioma extending into the optic canal: 2-dimensional operative video. Operative Neurosurgery. 2018 September 1;15(3):356 by permission of Oxford University Press. Cadaveric images provided by courtesy of: The Rhoton Collection. http://rhoton.ineurodb.org/.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
J. Li ◽  
Q. S. Ran ◽  
B. Hao ◽  
X. Xu ◽  
H. F. Yuan

The endoscopic transethmoidal approach is favored for the lack of external scars, a wide field of view, and rapid recovery time. But the effect of iatrogenic trauma should not be ignored due to the removal of the uncinate process and anterior and posterior ethmoidal sinus. Anatomically, the optic nerve is close to the sphenoid sinus and Onodi cell. In order to preserve the uncinate process and ethmoidal sinus, we perform endoscopic transsphenoidal optic canal decompression (ETOCD), which is less invasive. However, the anatomy of sphenoid sinus is quite variable, and the anatomical landmarks are rare. Therefore, identifying the position of optic canal is particularly important during surgery. To solve this, we use a postprocessing technique to identify the position of the optic nerve and internal carotid artery on the sphenoid sinus wall. Our results find that VA in 13 patients improved, with a total improve rate of 59.1%. No serious complications were found. We also found that the length of optic canal is different and the medial wall of the optic canal was the longest (p<0.05). The middle section of the optic canal is the narrowest, which was significantly different from cranial mouth and orbital mouth (p<0.05). We assumed that decompression may not require removal of all medial wall. If we remove the length of the shortest wall on the medial wall of the optic canal, the compression may be relieved. Thus, ETOCD was a feasible, safe, effective, and less-invasive approach for patients with TON. The CT postprocessing imaging facilitated recognition of the optic canal during surgery. The decompression length of the medial wall may not need to be completely removed, especially near the cranial mouth.


2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P74-P74 ◽  
Author(s):  
Catherine K Hart ◽  
Lee A Zimmer

Objective (1) Analyze the radiographic anatomy of the optic canal in relationship to the sphenoid sinus. (2) Understand the role variation in optic canal anatomy may have in the variability of outcomes in optic nerve decompression. Methods Fine cut computed tomography images of the sinuses were obtained with an IRB waiver. Optic canal dimensions were measured on sinus computed tomography images of 96 patients. 191 optic canals were analyzed (111 females, 80 males). Student T-test calculations were performed for statistical analysis on computer software. Results The average medial canal wall length was 1.48 centimeters (range 0.7–2.3). The length in males was 1.61 centimeters (1.1–2.3) as compared to 1.39 centimeters (0.7–2.0) in females (p=8.0–7). The average degree of exposure of the optic canal exposed to the sphenoid sinus was 101.3 degrees (56–176). The degree of exposure was 105.6 in males versus 98.2 in females (p=.01). The potential area of canal exposed to the sphenoid sinus was 0.66 centimeters squared or 28% of the total surface area. The potential area exposed to the sphenoid sinus in males was 0.76cm2 (28%) and 0.58 centimeters squared (27%) in females. Conclusions A wide range in medial canal wall length and exposure of the bony optic canal to the sphenoid sinus exists on CT images. The variation in medial canal wall length and in optic canal exposure to the sphenoid sinus may contribute to the variability in success rates of endoscopic optic nerve decompression for optic neuropathy.


Neurosurgery ◽  
2010 ◽  
Vol 66 (5) ◽  
pp. 883-892 ◽  
Author(s):  
Jeffrey P. Greenfield ◽  
Vijay K. Anand ◽  
Ashutosh Kacker ◽  
Michael J. Seibert ◽  
Ameet Singh ◽  
...  

Abstract OBJECTIVE The anterior skull base, in front of the sphenoid sinus, can be approached using a variety of techniques including extended subfrontal, transfacial, and craniofacial approaches. These methods include risks of brain retraction, contusion, cerebrospinal fluid leak, meningitis, and cosmetic deformity. An alternate and more direct approach is the endonasal, transethmoidal, transcribriform, transfovea ethmoidalis approach. METHODS An endoscopic, endonasal approach was used to treat a variety of conditions of the anterior skull base arising in front of the sphenoid sinus and between the orbits in a series of 44 patients. A prospective database was used to detail the corridor of approach, closure technique, use of intraoperative lumbar drainage, operative time, and postoperative complications. Extent of resection was determined by a radiologist using volumetric analysis. RESULTS Pathology included meningo/encephaloceles (19), benign tumors (14), malignant tumors (9), and infectious lesions (2). Lumbar drains were placed intraoperatively in 20 patients. The CSF leak rate was 6.8% for the whole series and 9% for intradural cases. Leaks were effectively managed with lumbar drainage. Early reoperation for cerebrospinal fluid (CSF) leak occurred in 1 patient (2.2%). There were no intracranial infections. Greater than 98% resection was achieved in 12 of 14 benign and 5 of 9 malignant tumors. CONCLUSION The endoscopic, endonasal, transethmoidal, transcribriform, transfovea ethmoidalis approach is versatile and suitable for managing a variety of pathological entities. This minimal access surgery is a feasible alternative to transcranial, transfacial, or combined craniofacial approaches to the anterior skull base and anterior cranial fossa in front of the sphenoid sinus. The risk of CSF leak and infection are reasonably low and decrease with experience. Longer follow-up and larger series of patients will be required to validate the long-term efficacy of this minimally invasive approach.


2021 ◽  
Vol 18 (1) ◽  
pp. 63-66
Author(s):  
Mohammed Dhaha ◽  
Abdelhafidh Sliman ◽  
Nadhir Karmeni ◽  
Sawsen Dhambri ◽  
Jalel Kallel

Encephaloceles are herniation of cranial content arising from a skull defect. Encephaloceles of the lateral wall of the sphenoid sinus (ELWSS) are  uncommon events. In most cases, these cranial hernias are secondary to trauma and craniofacial surgery. Spontaneous forms are evenrarer and not well understood. The most adopted hypothesis is a persisting Sternberg’s canal, an embryonic remnant connecting the middle cranial fossa and the nasopharynx. ELWSS are usually revealed by cerebrospinal fluid (CSF) leak. Diagnosis of this disease necessitates quick management due to the potential of lethal complications such as meningitis. We report the case of a spontaneous ELWSS in a 53-year-old woman revealed by CSF leak which was successfully managed with a conventional transcranial approach. We focus on the clinical aspect and pathogenesis of the disease, and discuss the main possible surgical approaches. Keywords: Spontaneous encephalocele, Sphenoid sinus, CSF leak, Transcranial approach


2018 ◽  
Vol 129 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Chirag R. Patel ◽  
Eric W. Wang ◽  
Juan C. Fernandez-Miranda ◽  
Paul A. Gardner ◽  
Carl H. Snyderman

OBJECTIVEThe endoscopic endonasal approach (EEA) has been shown to be an effective means of accessing lesions of the petrous apex. Lesions that are lateral to the paraclival segment of the internal carotid artery (ICA) require lateralization of the paraclival segment of the ICA or a transpterygoid infrapetrous approach. In this study the authors studied the feasibility of adding a contralateral transmaxillary (CTM) corridor to provide greater access to the petrous apex with decreased need for manipulation of the ICA.METHODSUsing image guidance, EEA and CTM extension were performed bilaterally on 5 cadavers. The anterior wall of the sphenoid sinus and rostrum were removed. The angle of the surgical approach from the axis of the petrous segment of the ICA was measured. Five illustrative clinical cases are presented.RESULTSThe CTM corridor required a partial medial maxillectomy. When measured from the axis of the petrous ICA, the CTM corridor decreased the angle from 44.8° ± 2.78° to 20.1° ± 4.31°, a decrease of 24.7° ± 2.58°. Drilling through the CTM corridor allowed the drill to reach lateral aspects of the petrous apex that would have required lateralization of the ICA or would not have been accessible via EEA. The CTM corridor allowed us to achieve gross-total resection of the petrous apex region in 5 clinical cases with significant paraclival extension.CONCLUSIONSThe CTM corridor is a feasible extension to the standard EEA to the petrous apex that offers a more lateral trajectory with improved access. This approach may reduce the risk and morbidity associated with manipulation of the paraclival ICA.


2018 ◽  
Vol 17 (1) ◽  
Author(s):  
Nawal Ahmed ◽  
Emad Nafie ◽  
Radhiana Hassan ◽  
Hafizah Binti Pasi

Introduction: Sphenoid sinus is the most variable structure in human. The prevalence of anatomical variations varies with the population. Increasing endoscopic procedures around the sphenoid sinus and advances in imaging techniques, allowed precise evaluation of sinus anatomical variation in each population. This study measured the prevalences and described the variations of the sphenoid sinus using thin slice contrasted computed tomography scan of brain scans. Materials and Methods: A retrospective cross-sectional study of 250 brain scans of patients between 18-60 years old attending Hospital Tengku Ampuan Afzan, Kuantan, Pahang from 1st January to 31st December 2017. The sphenoid sinus pneumatization types, volume, optic nerve relation according to Delano’s classification, internal carotid artery relation, and the number of sinus septum and attachment site were studied. Results: Post sellar pneumatization type was most common (52%). The mean sinus volume was 19 cm³ which was significantly different between genders. Delano optic nerve type 1 was most frequent (43%) and most were seen bilaterally with significant differences between gender. The internal carotid artery was seen non-protruded 41.6% cases, protruded in 36.4% cases, and protrusion with wall dehiscence in 22% cases. Two septate sinuses were more prominent (44.3%), aseptate sinus in 2.4% cases. The principle septa attachment site was sella (28%), internal carotid artery related septa found in 10% cases and 3.2% of cases with optic nerve septal attachment. Conclusion: This study revealed the presence of all sphenoid sinus variations amongst the study population. The preoperative determination of these anatomical variations minimizes vital neurovascular structures injury.


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